Sofa



FIG. 1 is a perspective view of the sofa;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof, the right side being a mirror image;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines in the figures are for the purpose of illustrating portions of the sofa, which form no part of the claimed design. 

CLAIM The ornamental design for a sofa, as shown and described. 